Dizziness: A Merck Manual of Patient Symptoms podcast

Dizziness is an imprecise term patients often use to describe various related sensations, including

• Faintness (a feeling of impending syncope)
• Light-headedness
• Feeling of imbalance or unsteadiness
• A vague spaced-out or swimmy-headed feeling

Vertigo is a false sensation of movement of the self or the environment. Usually the perceived movement is rotary—a spinning or wheeling sensation—but some patients simply feel pulled to one side. Vertigo is not a diagnosis—it is a description of a sensation.

Both sensations may be accompanied by nausea and vomiting or difficulty with balance, gait, or both.

Perhaps because these sensations are hard to describe in words, patients often use “dizziness,” “vertigo,” and other terms interchangeably and inconsistently. Different patients with the same underlying disorder may describe their symptoms very differently. A patient may even give different descriptions of the same “dizzy” event during a given visit depending on how the question is asked. Because of this discrepancy, even though vertigo seems to be a clearly delineated subset of dizziness, many clinicians prefer to consider the two symptoms together.

However they are described, dizziness and vertigo may be disturbing and even incapacitating, particularly when accompanied by nausea and vomiting. Symptoms cause particular problems for people doing an exacting or dangerous task, such as driving, flying, or operating heavy machinery.

Dizziness accounts for about 5 to 6% of physician visits. It may occur at any age but becomes more common with increasing age; it affects about 40% of people over 40 yr at some time. Dizziness may be temporary or chronic. Chronic dizziness, defined as lasting > 1 mo, is more common among elderly people.

Pathophysiology

The vestibular system is the main neurologic system involved in balance. This system includes

• The vestibular apparatus of the inner ear
• The 8th (vestibulocochlear) cranial nerve, which conducts signals from the vestibular apparatus to the central components of the system
• The vestibular nuclei in the brain stem and cerebellum

Disorders of the inner ear and 8th cranial nerve are considered peripheral disorders. Those of the vestibular nuclei and their pathways in the brain stem and cerebellum are considered central disorders.

The sense of balance also incorporates visual input from the eyes and proprioceptive input from the peripheral nerves (via the spinal cord). The cerebral cortex receives output from the lower centers and integrates the information to produce the perception of motion.

Vestibular apparatus: Perception of stability, motion, and orientation to gravity originates in the vestibular apparatus, which consists of

• The 3 semicircular canals
• The 2 otolith organs—the saccule and utricle

Rotary motion causes flow of endolymph in the semicircular canal oriented in the plane of motion. Depending on the direction of flow, endolymph movement either stimulates or inhibits neuronal output from hair cells lining the canal. Similar hair cells in the saccule and utricle are embedded in a matrix of Ca carbonate crystals (otoliths). Deflection of the otoliths by gravity stimulates or inhibits neuronal output from the attached hair cells.

Etiology

There are numerous structural (trauma, tumors, degenerative), vascular, infectious, toxic (including drug-related), and idiopathic causes (see Table 4: Approach to the Patient With Ear Problems: Some Causes of Dizziness and Vertigo), but only about 5% of cases are caused by a serious disorder.

The most common causes of dizziness with vertigo involve some component of the peripheral vestibular system:

• Benign positional vertigo
• Meniere's disease
• Vestibular neuronitis
• Labyrinthitis

Less often, the cause is a central vestibular disorder (most commonly migraine), a disorder with a more global effect on cerebral function, a psychiatric disorder, or a disorder affecting visual or proprioceptive input. Sometimes, no cause can be found.

The most common causes of dizziness without vertigo are less clear cut, but they are usually not otologic and probably are

• Drug effects
• Multifactorial or idiopathic

Nonneurologic disorders with a more global effect on cerebral function sometimes manifest as dizziness and rarely as vertigo. These disorders typically involve inadequate substrate (eg, O₂, glucose) delivery caused by hypotension, hypoxemia, anemia, or hypoglycemia; when severe, some of these disorders may manifest as syncope. Additionally, certain hormonal changes (eg, as with thyroid disease, menstruation, pregnancy) can cause dizziness. Numerous CNS-active drugs can cause dizziness independent of any toxic effect on the vestibular system.

Occasionally, dizziness and vertigo may be psychogenic. Patients with panic disorder, hyperventilation syndrome, anxiety, or depression may present with complaints of dizziness.

In elderly patients, dizziness is often multifactorial secondary to drug adverse effects and age-diminished visual, vestibular, and proprioceptive abilities. Two of the most common specific causes are disorders of the inner ear: benign paroxysmal positional vertigo and Meniere's disease.

Table 4
PrintOpen table in new window
Some Causes of Dizziness and Vertigo Cause Suggestive Findings Diagnostic Approach Peripheral vestibular system disordersa,b Benign positional vertigo Severe, brief (< 1 min) spinning triggered by moving head in a specific direction Nystagmus has a latency of 1–10 sec, is fatigable, and is torsional, beating toward the undermost ear Frenzel lenses needed to prevent visual fixation Hearing and neurologic examination intact Dix-Hallpike maneuver to assess characteristic positional nystagmus Meniere's disease Recurrent episodes of unilateral tinnitus, hearing loss, ear fullness Audiogram and gadolinium-enhanced MRI to rule out other causes Vestibular neuronitis (viral cause suspected) Sudden, incapacitating, severe vertigo with no hearing loss or other findings Lasts up to 1 wk, with gradual lessening of symptoms Positional vertigo may result Clinical evaluation Gadolinium-enhanced MRI Labyrinthitis (viral or bacterial) Hearing loss, tinnitus Temporal bone CT if purulent infection suspected Gadolinium-enhanced MRI if unilateral hearing loss and tinnitus Otitis media (acute or chronic, sometimes with cholesteatoma) Ear pain, abnormal ear examination, including discharge if chronic otitis History of infection Clinical evaluation CT if cholesteatoma to rule out semicircular canal fistula formation Trauma (eg, tympanic membrane rupture, labyrinthine contusion, perilymphatic fistula, temporal bone fracture, postconcussion) Trauma obvious on history Other findings depending on location and extent of damage CT depending on cause and findings Acoustic neuroma Slowly progressive unilateral hearing loss, tinnitus, dizziness, dysequilibrium Rarely, facial numbness, weakness, or both Audiogram Gadolinium-enhanced MRI if significant hearing asymmetry or unilateral tinnitus Ototoxic drugsc Treatment with aminoglycoside drugs recently instituted, usually with bilateral hearing loss and vestibular loss Clinical evaluation Vestibular evaluation with electronystagmography and rotary chair tests Herpes zoster oticus (Ramsay Hunt syndrome) Also affects geniculate ganglion, so facial weakness and taste loss often manifest along with hearing loss Vertigo possible but not typical Vesicles present on pinna and in ear canal Clinical evaluation Chronic motion sickness (mal de debarquement) Persistent symptoms after acute motion sickness Clinical evaluation Central vestibular system disordersd Brain stem hemorrhage or infarction Sudden onset Involvement of cochlear artery possibly causing ear symptoms Immediate imaging Gadolinium-enhanced MRI if available, otherwise CT Cerebellar hemorrhage or infarction Sudden onset, with ataxia and other cerebellar findings, often headache Deteriorates rapidly Immediate imaging Gadolinium-enhanced MRI if available, otherwise CT Migraine Episodic, recurrent vertigo, usually without auditory symptoms Possibly headache, but often personal or family history of migraine Photophobia, phonophobia, visual or other auras possible, helping make diagnosis Usually clinical examination but with imaging to rule out other causes Trial of migraine prophylaxis Multiple sclerosis Varied CNS motor and sensory deficits, with remissions and recurring exacerbations Gadolinium-enhanced MRI of brain and spine Vertebral artery dissection Often head and neck pain Magnetic resonance angiography Vertebrobasilar insufficiency Intermittent brief episodes, sometimes with drop attacks, visual disturbance, confusion Magnetic resonance angiography Global disturbance of CNS functione Anemia (numerous causes) Pallor, weakness, sometimes heme-positive stool CBC CNS-active drugsf (not ototoxic) Drug recently instituted or dose increased; multiple drugs, particularly in an elderly patient Symptoms unrelated to movement or position Sometimes, drug levels (certain anticonvulsants) Trial of withdrawal Hypoglycemia (usually caused by drugs for diabetes) Recent dose increase Sometimes sweating Fingerstick glucose test (during symptoms if possible) Hypotension (caused by cardiac disorders, antihypertensives, blood loss, dehydration, or orthostatic hypotension syndromes including postural orthostatic tachycardia syndrome and other dysautonomias) Symptoms on arising, sometimes with vagal stimulation (eg, urination) but not with head motion or while recumbent Manifestation possibly dominated by cause (eg, blood loss, diarrhea) Orthostatic vital signs, sometimes with tilt table test, ECG Other testing directed at suspected cause Hypoxemia (numerous causes) Tachypnea Often history of lung disease Pulse oximetry Other causese Pregnancy May be unrecognized Pregnancy test Psychiatric (eg, panic attack, hyperventilation syndrome, anxiety, depression) Symptoms chronic, brief, recurrent Unrelated to movement or position but may occur with stress or upset Neurologic and ENT examinations normal Initially, patient may be diagnosed with peripheral vestibular dysfunction and fail to respond to appropriate management Clinical evaluation Syphilis Chronic symptoms with bilateral hearing loss, fluctuating, with episodic vertigo Syphilis serology Thyroid disorders Weight change Heat or cold intolerance Thyroid function testing aSymptoms are typically paroxysmal, severe, and episodic rather than continuous. Ear symptoms (eg, tinnitus, fullness, hearing loss) usually indicate a peripheral disorder. Loss of consciousness is not associated with dizziness due to peripheral vestibular pathology. bPeripheral vestibular system disorders are listed in rough order of frequency of occurrence. cNumerous drugs, including aminoglycosides, chloroquineSome Trade Names ARALEN Click for Drug Monograph , furosemideSome Trade Names LASIX Click for Drug Monograph , and quinineSome Trade Names QUALAQUIN Click for Drug Monograph . Many other drugs are ototoxic but have more effect on the cochlea than the vestibular apparatus. dEar symptoms are rarely present, but gait/balance disturbance is common. Nystagmus is not inhibited by visual fixation. eShould not manifest otic symptoms (eg, hearing loss, tinnitus) or focal neurologic deficit (sometimes occurs with hypoglycemia). Vertiginous symptoms are rare but have been reported. fNumerous drugs, including most antianxiety, anticonvulsant, antidepressant, antipsychotic, and sedative drugs. Also includes drugs used to treat vertigo. Some Causes of Dizziness and Vertigo Cause Suggestive Findings Diagnostic Approach Peripheral vestibular system disordersa,b Benign positional vertigo Severe, brief (< 1 min) spinning triggered by moving head in a specific direction Nystagmus has a latency of 1–10 sec, is fatigable, and is torsional, beating toward the undermost ear Frenzel lenses needed to prevent visual fixation Hearing and neurologic examination intact Dix-Hallpike maneuver to assess characteristic positional nystagmus Meniere's disease Recurrent episodes of unilateral tinnitus, hearing loss, ear fullness Audiogram and gadolinium-enhanced MRI to rule out other causes Vestibular neuronitis (viral cause suspected) Sudden, incapacitating, severe vertigo with no hearing loss or other findings Lasts up to 1 wk, with gradual lessening of symptoms Positional vertigo may result Clinical evaluation Gadolinium-enhanced MRI Labyrinthitis (viral or bacterial) Hearing loss, tinnitus Temporal bone CT if purulent infection suspected Gadolinium-enhanced MRI if unilateral hearing loss and tinnitus Otitis media (acute or chronic, sometimes with cholesteatoma) Ear pain, abnormal ear examination, including discharge if chronic otitis History of infection Clinical evaluation CT if cholesteatoma to rule out semicircular canal fistula formation Trauma (eg, tympanic membrane rupture, labyrinthine contusion, perilymphatic fistula, temporal bone fracture, postconcussion) Trauma obvious on history Other findings depending on location and extent of damage CT depending on cause and findings Acoustic neuroma Slowly progressive unilateral hearing loss, tinnitus, dizziness, dysequilibrium Rarely, facial numbness, weakness, or both Audiogram Gadolinium-enhanced MRI if significant hearing asymmetry or unilateral tinnitus Ototoxic drugsc Treatment with aminoglycoside drugs recently instituted, usually with bilateral hearing loss and vestibular loss Clinical evaluation Vestibular evaluation with electronystagmography and rotary chair tests Herpes zoster oticus (Ramsay Hunt syndrome) Also affects geniculate ganglion, so facial weakness and taste loss often manifest along with hearing loss Vertigo possible but not typical Vesicles present on pinna and in ear canal Clinical evaluation Chronic motion sickness (mal de debarquement) Persistent symptoms after acute motion sickness Clinical evaluation Central vestibular system disordersd Brain stem hemorrhage or infarction Sudden onset Involvement of cochlear artery possibly causing ear symptoms Immediate imaging Gadolinium-enhanced MRI if available, otherwise CT Cerebellar hemorrhage or infarction Sudden onset, with ataxia and other cerebellar findings, often headache Deteriorates rapidly Immediate imaging Gadolinium-enhanced MRI if available, otherwise CT Migraine Episodic, recurrent vertigo, usually without auditory symptoms Possibly headache, but often personal or family history of migraine Photophobia, phonophobia, visual or other auras possible, helping make diagnosis Usually clinical examination but with imaging to rule out other causes Trial of migraine prophylaxis Multiple sclerosis Varied CNS motor and sensory deficits, with remissions and recurring exacerbations Gadolinium-enhanced MRI of brain and spine Vertebral artery dissection Often head and neck pain Magnetic resonance angiography Vertebrobasilar insufficiency Intermittent brief episodes, sometimes with drop attacks, visual disturbance, confusion Magnetic resonance angiography Global disturbance of CNS functione Anemia (numerous causes) Pallor, weakness, sometimes heme-positive stool CBC CNS-active drugsf (not ototoxic) Drug recently instituted or dose increased; multiple drugs, particularly in an elderly patient Symptoms unrelated to movement or position Sometimes, drug levels (certain anticonvulsants) Trial of withdrawal Hypoglycemia (usually caused by drugs for diabetes) Recent dose increase Sometimes sweating Fingerstick glucose test (during symptoms if possible) Hypotension (caused by cardiac disorders, antihypertensives, blood loss, dehydration, or orthostatic hypotension syndromes including postural orthostatic tachycardia syndrome and other dysautonomias) Symptoms on arising, sometimes with vagal stimulation (eg, urination) but not with head motion or while recumbent Manifestation possibly dominated by cause (eg, blood loss, diarrhea) Orthostatic vital signs, sometimes with tilt table test, ECG Other testing directed at suspected cause Hypoxemia (numerous causes) Tachypnea Often history of lung disease Pulse oximetry Other causese Pregnancy May be unrecognized Pregnancy test Psychiatric (eg, panic attack, hyperventilation syndrome, anxiety, depression) Symptoms chronic, brief, recurrent Unrelated to movement or position but may occur with stress or upset Neurologic and ENT examinations normal Initially, patient may be diagnosed with peripheral vestibular dysfunction and fail to respond to appropriate management Clinical evaluation Syphilis Chronic symptoms with bilateral hearing loss, fluctuating, with episodic vertigo Syphilis serology Thyroid disorders Weight change Heat or cold intolerance Thyroid function testing aSymptoms are typically paroxysmal, severe, and episodic rather than continuous. Ear symptoms (eg, tinnitus, fullness, hearing loss) usually indicate a peripheral disorder. Loss of consciousness is not associated with dizziness due to peripheral vestibular pathology. bPeripheral vestibular system disorders are listed in rough order of frequency of occurrence. cNumerous drugs, including aminoglycosides, chloroquineSome Trade Names ARALEN Click for Drug Monograph , furosemideSome Trade Names LASIX Click for Drug Monograph , and quinineSome Trade Names QUALAQUIN Click for Drug Monograph . Many other drugs are ototoxic but have more effect on the cochlea than the vestibular apparatus. dEar symptoms are rarely present, but gait/balance disturbance is common. Nystagmus is not inhibited by visual fixation. eShould not manifest otic symptoms (eg, hearing loss, tinnitus) or focal neurologic deficit (sometimes occurs with hypoglycemia). Vertiginous symptoms are rare but have been reported. fNumerous drugs, including most antianxiety, anticonvulsant, antidepressant, antipsychotic, and sedative drugs. Also includes drugs used to treat vertigo.

Evaluation

History: History of present illness should cover the sensations felt; an open-ended question is best (eg, “Different people use the word ‘dizziness' differently. Can you please describe as thoroughly as you can what you feel?”). Brief, specific questioning as to whether the feeling is faintness, light-headedness, loss of balance, or vertiginous may bring some clarity, but persistent efforts to categorize a patient's sensations are unnecessary. Other elements are more valuable and clear-cut:

• Severity of initial episode
• Severity and characteristics of subsequent episodes
• Symptoms continuous or episodic
• If episodic, frequency and duration
• Triggers and relievers (ie, triggered by head/body position change)
• Associated aural symptoms (eg, hearing loss, ear fullness, tinnitus)
• Severity and related disability

Is the patient having a single, sudden, acute event, or has dizziness been chronic and recurrent? Was the first episode the most severe (vestibular crisis)? How long do episodes last, and what seems to trigger and worsen them? The patient should be asked specifically about movement of the head, arising, being in anxious or stressful situations, and menses. Important associated symptoms include headache, hearing loss, tinnitus, nausea and vomiting, impaired vision, focal weakness, and difficulty walking. The severity of impact on the patient's life should be estimated: Has the patient fallen? Is the patient reluctant to drive or leave the house? Has the patient missed work days?

Review of systems should seek symptoms of causative disorders, including URI symptoms (inner ear disorders); chest pain, palpitations, or both (heart disease); dyspnea (lung disease); dark stools (anemia caused by GI blood loss); and weight change or heat or cold intolerance (thyroid disease).

Past medical history should note presence of recent head trauma (usually obvious), migraine, diabetes, heart or lung disease, and drug and alcohol abuse. In addition to identifying all current drugs, drug history should assess recent changes in drugs, doses, or both.

Physical examination: Examination begins with a review of vital signs, including presence of fever, rapid or irregular pulse, and supine and standing BP, noting any drop in BP on standing up (orthostatic hypotension) and whether standing provokes symptoms. If standing does provoke symptoms, postural symptoms should be distinguished from those triggered by head movement by returning the patient supine until symptoms dissipate and then rotating the head.

The ENT and neurologic examinations are fundamental. Specifically, with the patient supine, the eyes are checked for presence, direction, and duration of spontaneous nystagmus (for full description of examination for nystagmus, see Sidebar 1: Approach to the Patient With Ear Problems: Nystagmus). Direction and duration of nystagmus and development of vertigo are noted.

A gross bedside hearing test is done, the ear canal is inspected for discharge and foreign body, and the tympanic membrane is checked for signs of infection or perforation.

Cerebellar function is tested by assessing gait and doing a finger-nose test and Romberg's test. The remainder of the neurologic examination is done, including testing the rest of the cranial nerves.

Red flags: The following findings are of particular concern:

• Head or neck pain
• Ataxia
• Loss of consciousness
• Focal neurologic deficit

Interpretation of findings: Traditionally, differential diagnosis has been based on the exact nature of the chief complaint (ie, distinguishing dizziness from light-headedness from vertigo). However, the inconsistency of patients' descriptions and the poor specificity of symptoms make this unreliable. A better approach places more weight on the onset and timing of symptoms, the triggers, and associated symptoms and findings, particularly otologic and neurologic ones.

Some constellations of findings are highly suggestive (see Table 4: Approach to the Patient With Ear Problems: Some Causes of Dizziness and Vertigo), particularly those that help differentiate peripheral from central vestibular disorders.

• Peripheral: Ear symptoms (eg, tinnitus, fullness, hearing loss) usually indicate a peripheral disorder. They are typically associated with vertigo and not generalized dizziness (unless caused by uncompensated peripheral vestibular weakness). Symptoms are usually paroxysmal, severe, and episodic; continuous dizziness is rarely due to peripheral vertigo. Loss of consciousness is not associated with dizziness due to peripheral vestibular pathology.
• Central: Ear symptoms are rarely present, but gait/balance disturbance is common. Nystagmus is not inhibited by visual fixation.

Testing: Patients with a sudden, ongoing attack should have pulse oximetry and fingerstick glucose test. Women should have a pregnancy test. Most clinicians also do an ECG. Other tests are done based on findings (see Table 4: Approach to the Patient With Ear Problems: Some Causes of Dizziness and Vertigo), but generally gadolinium-enhanced MRI is indicated for patients with acute symptoms who have headache, neurologic abnormalities, or any other findings suggestive of a CNS etiology.

Patients with chronic symptoms should have gadolinium-enhanced MRI to look for evidence of stroke, multiple sclerosis, or other CNS lesions.

Patients for whom results of bedside tests of hearing and vestibular function are abnormal or equivocal should undergo formal testing with audiometry and electronystagmography.

Laboratory tests are rarely helpful, except for patients with chronic vertigo and bilateral hearing loss, for whom syphilis serology is indicated.

Treatment

Treatment is directed at the cause, including stopping, reducing, or switching any causative drugs.

If a vestibular disorder is present and thought to be secondary to active Meniere's disease or vestibular neuronitis or labyrinthitis, the most effective vestibular nerve suppressants are diazepamSome Trade Names
VALIUM
Click for Drug Monograph
(2 to 5 mg po q 6 to 8 h, with higher doses given under supervision for severe vertigo) or oral antihistamine/anticholinergic drugs (eg, meclizineSome Trade Names
ANTIVERT
BONINE
Click for Drug Monograph
25 to 50 mg tid). All of these drugs can cause drowsiness, thereby limiting their use for certain patients. Nausea can be treated with prochlorperazineSome Trade Names
COMPAZINE
Click for Drug Monograph
10 mg IM qid or 25 mg rectally bid. Vertigo associated with benign paroxysmal positional vertigo is treated with the Epley maneuver (otolith repositioning) done by an experienced practitioner (see Inner Ear Disorders: The Epley maneuver.). Meniere's disease is best managed by an otolaryngologist with training in management of this chronic disorder, but initial management consists of a low-salt diet and a K-sparing diuretic.

Patients with persistent or recurrent vertigo secondary to unilateral vestibular weakness (such as secondary to vestibular neuronitis) usually benefit from vestibular rehabilitation therapy done by an experienced physical therapist. Most patients compensate well, although some, especially the elderly, have more difficulty. Physical therapy can also provide important safety information for elderly or particularly disabled patients.

Geriatrics Essentials

As people age, organs involved in balance function less well. For example, seeing in dim light becomes more difficult, inner ear structures deteriorate, proprioception becomes less sensitive, and mechanisms that control BP become less responsive (eg, to postural changes, postprandial demands). Older people also are more likely to have cardiac or cerebrovascular disorders that can contribute to dizziness. They also are more likely to be taking drugs that can cause dizziness, including those for hypertension, angina, heart failure, seizures, and anxiety, as well as certain antibiotics, antihistamines, and sleep aids. Thus, dizziness in elderly patients usually has more than one cause.

Although unpleasant at any age, the consequences of dizziness and vertigo are a particular problem for elderly patients. Those with frailty are at significant risk of falling with consequent fractures; their fear of moving and falling often significantly decreases their ability to do daily activities.

In addition to treatment of specific causes, elderly patients with dizziness or vertigo may benefit from physical therapy and exercises to strengthen muscles and help maintain independent ambulation as long as possible.

Key Points

• Vague or inconsistently described symptoms may still be associated with a serious condition.
• Cerebrovascular disease and drug effects should be sought, particularly in elderly patients.
• Peripheral vestibular system disorders should be differentiated from central vestibular system disorders.
• Immediate neuroimaging should be done when symptoms are accompanied by headache, focal neurologic abnormalities, or both.

Last full review/revision January 2009 by Debara L. Tucci, MD, MS

Content last modified February 2012